This invention relates to the incorporation of a dye acceptor into a polyester.
Synthetic fibers and films, such as those made from polyesters among others, have found a very wide utility in recent years. In the continuing improvement of such materials, there is a need for improving the dyeability of polyesters to enhance their value in the form of fibers and fabrics prepared therefrom.
The incorporation of some form of a dye acceptor has generally been found necessary to produce easily and satisfactorily dyed polyester fibers. However, the incorporation of a given material to provide this function runs the risk of disturbing other properties of the polyester such that a modified polyester composition may have been simultaneously rendered more dyeable, but less suitable for fiber formation. Indeed, the incorporation of some dye acceptors have caused a deterioration of polymer properties such as color, molecular weight, melting point, glycol ether content, and the like. Fibers, spun from such polymers, have suffered correspondingly
A class of dyeability-additives typified by sodium p-phenolsulfonate is such an additive in point. This additive dramatically improves the dyeability of polyester with basic dyes but substantially reduces the suitability of the polyester for spinning into fibers.